Unmanned aerial vehicles (UAVs) are aircraft with no human pilot onboard that are often operated with assistance from ground-based personnel and/or systems. The use of UAVs has been increasing as the need for such aircraft grows and advances in UAV technology make UAVs more capable and less expensive. Applications of UAVs include use both military applications and civilian applications such as policing, firefighting, and surveillance. UAVs powered by internal combustion engines carry their own fuel supply that is necessarily limited. Operators of UAVs have to estimate remaining flight time for an operating UAV based on the amount of fuel remaining onboard the UAV and the rate of fuel consumption, which may be estimated using various methods.